9:48:00 2/29/2008 AM Infectious diseases in urban populations Crowd diseases of overriding importance o Rats on ship carried fleas which in turn caused the plague Malnutrition decreases resistance to infectious diseases Social stratification leads to variation in sanitation, general health, and exposure to infectious organisms Interesting examples of biological polymorphism in humans RBC Phenotypes ABO MN Rh WBC phenotypes o HLA (human leukocyte antigen) Six loci = hundreds of alleles The most polymorphic genetic system known in humans HLA useful in studies of human population diversity Some populations differ in HLA allele frequencies from other European populations o Lapps o Sardinians o Basques Australians New Guineans
also
Some HLA antigens are associated with varied resistance to diseases such s malaria, hepatitis B, and HIV Some individuals possess a natural immunity to HIV infection Genetic mutation in protein receptor site on T cells: o Homozygotes resistant to HIV o Heterozygotes slowed course of disease Mutation occurs mainly in people of European descent 10% are immune to HIV o Other populations not so much Japanese and west Africans mutation absent o 2% of frican Americans have mutation genetic admixture some virus uses same T cell receptor site as HIV so a small number of those populations would also have immunity to HIV o possibly smallpox!
HLA also involved in male fertility and ability for PTC (phelylthiocarbamide) tasting Bitter tasters can detect toxic plants (deadly nightshade) Human biocultural evolution: the interaction of cultural and forces of evolution Lactose intolerance: inability to digest milk In all populations children have the ability to digest milk they produce lactase (enzyme that aids in the digestion of milk) that breaks down lactose (milk sugar) In human evolution milk was unavailable to children after weaning European populations generally are lactose tolerant o They descend from pastoralists o There is some variation in lactase production o Populations that process milk (yogurt, cheese) have high levels of lactose intolerance o There is an advantage to lactase production in pastoralists populations (selective pressure) for lactase production o Most African populations have high frequency of lactose intolerance o A few african groups that have traditionally been pastoralists have high frequencies of lactose tolerance o
Chapter 5
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mammalian characteristics behavioral flexibility asses a situation and respond appropriately long gestations mammary glands nursing their young heterodont different types of teeth homeothermy warm blooded, don't have to rely on environment to maintain their body temperature larger brains hair endothermic able to maintain internal body temperature by metabolic processes (mammals, birds and possibly dinosaurs) What is a species? Animals are members of the same species if normal males and females are actively or potentially capable of mating and producing fertile offspring in a natural environment Two animals whose species name is different are assumed to be incapable of interbreeding and producing fertile offspring If the species name is the same but the genus name is different, the animals cannot interbreed. Two animals who share a species name but differ at the subspecies level are assumed be to capable of producing fertile offspring Different species are assumed to be incapable of interbreeding and producing fertile offspring Different subspecies but same species and genus are assumed to be capable of producing fertile offspring Biological species a group of individuals capable of fertile interbreeding but reproductively isolated from other such groups. Incipient species speciation in process Speciation species formation Two primary mechanisms of speciation o Allopatric speciation occurs as a consequence of geographic separation followed by genetic differentiation o Sympatric speciation involves behavioral separation rather than geographic separation
Chapter 6 Primates
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what are the unique characteristics of primates? Primate teeth: dental formula 2123 o 2 incisors, 1 canine, 2 premolars, 3 molars some o o o o o o o o o o o o o primate characteristics: reduced snout binocular vision finger and toe nails reduced birth numbers prehensile hands and feet omnivorous social diurnal (function during the day) larger primate brain flatter molar cusps shorter snout fused mandible post orbital plate holds your eyeball
two most defining characteristics of primates o post orbital bar bar that goes all around the eye o derivation of the auditory bulla - located within temperal lobe taxonomic classification o primate anthropoid catarrhine hominoid hominid Homo sapiens prosimians tarsiers, lemurs, lorises anthropoids platyrrhines, catarrhines, ceboids, cercopithecoids, hominoids suborder: Strepsirhines lemurs, lorises, and galagos old world o Madagascar, Africa, Asia Great variation in adaptation Great variation in social structure Primitive characteristics (Suborder: Prosimii also includes tarsiers) Strepsirhines characteristics small body size Olfaction important
o Moist, fleshy nose (rhinarium) o Relatively long snout o Most mark territory with scent Relatively small brain Most are nocturnal Most lack color vision (don't need it at night) Dental comb Grooming claw More laterally positioned eyes Postorbital bar Unfused mandible Varied dental formula: o Lemurs 2:1:3:3 o Indris 2:1:2:3 (top) / 1:1:2:3 (bottom) Molars with high pointy cusps Lemurs Madagascar only More than 30 species Great species variation Mostly arboreal (tree dwelling) but many terrestrial species Adaptive radiation rapid expansion and diversification of species into new ecological niches Environment o Arboreal / terrestrial Body size o 5" 24" Feeding behavior o Large diurnal and eat fruits, buds, leaves, bark, etc o Small nocturnal and eat insects Locomotion o Arboreal quadrupeds o Terrestrial quadrupeds o Vertical clingers and leapers Social organization o Gregarious 10 25 individuals o Monogamous families
o Solitary Lorises Forests of India, Sri Lanka, Southeast Asia, and Africa Only 5 species Nocturnal fill niches not occupied by monkeys Competitive exclusion when two or more species compete for the same niche, one either becomes extinct or undergoes character displacement Feeding behavior o Mainly insectivorous o Different sized lorises occupy different levels of the forest canopy Locomotion o Slow arboreal quadrupedalism Social organization o Solitary o Family unit Galagos Africa Bush baby 10 species nocturnal arboreal solitary Active clingers and leapers